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3v motor, 12v power supply

I have a 3v DC motor, a 12v power supply, and various resistors. Can I use resistors in series with the motor to keep it from burning up?

kelseymh7 years ago
You can in principle, but you're likely to burn up the resistors instead.  What kind of current does the motor draw?  You need use V=IR to figure out what resistance R you need to get the 9V drop for your motor.  Then you need to compute P=I2R to know how much power (watts) those resistors are going to have to dissipate.  If you're using typical 1/4W resistors, then you'd better have P < 0.25.